Optimization of the box section of the main girders of the bridge crane by using the method of Lagrange multipliers

Abstract

The paper considers the problem of optimization of the box section of the main girder of the bridge crane for the case of placing the rail above the web plate. Reduction of the girder mass is set as the objective function. The method of Lagrange multiplier was used as the methodology for approximate determination of optimum dependences of geometrical parameters of the box section. The criterion of strength were applied as the constraint function. The analysis of the optimization results and the solutions was the basis for recommendations which are significant for designers during construction of cranes.